Greek defence minister Panos Kammenos said the aircraft was in Egyptian airspace and flying at 37,000ft when it made "sudden swerves" and plunged to 15,000ft.

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Video:Egypt Statement On Missing Plane

He said it swerved "90 degrees left and then 360 degrees to the right" before vanishing.

Flight MS804 departed from the French capital at 10.09pm BST. The airline said the plane lost contact with radar at 1.30am BST. It was last in touch 10 minutes earlier.

At that stage the Airbus A320, which was 13 years old and had logged 48,000 flight hours, was about three hours and 40 minutes into the four-hour journey.

Military search and rescue teams picked up an automated signal from the plane's emergency beacon at 3.26am BST - about 80 minutes after it was supposed to land in Cairo. It is thought this may have been triggered on impact.

Thirty Egyptians, 15 French, two Iraqis, a Belgian, a Kuwaiti, a Saudi, a Sudanese, a Chadian, an Algerian, a Portuguese and a Canadian were among the passenger list, which also included one child and two babies.

Greek and French boats and planes have joined teams from the Egyptian armed forces in the search for the jet.

Greece also has a submarine on standby, while Britain and the US have offered their support.

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Video:What Happened To Flight MS804?

Foreign Secretary Philip Hammond said: "My thoughts are with the family and friends of all those missing following the disappearance of EgyptAir's flight MS804.

"We are in close contact with Egyptian and French authorities and have offered the Egyptian authorities our support in their search and rescue efforts."

Greek civil aviation authorities said the jet disappeared off its radar two minutes after leaving its airspace. Prior to that, its air traffic controllers spoke to the pilot who reported no problems.